Decompression without compression (for lack of a better name). We store into Cassandra log batches that come in over http either uncompressed, deflate, snappy. We just add 'magic e.g. \0 \s \n \a \p \p \y as a prefix to the column value so we can decode it when serve it back up.
Seems like Cassandra could detect data with the appropriate magic, store as is and decode for us automatically on the way back. Colin.